THE EXAGGERATED MORPHOLOGICAL AND PHYSIOLOGICAL POLARITY OF THE GERM TISSUE IN THE TELEOTROPHIC OVARIOLES OF RHODNIUS MAKE IT AN EXCELLENT MODEL TO EXAMINE THE ROLE OF ION CURRENTS IN NURSE CELLS - OOCYTE POLARITY. BUILDING ON OUR PREVIOUS WORK WITH THE VOLTAGE VIBRATING PROBE AND PRELIMINARY ION-SELECTIVE PROBE WORK DURING THE SUMMER 1994, I INTEND TO INVESTIGATE THE MAGNITUDE, TIMING AND PATTERN OF THE CA2+ AND NA+ DRIVEN CURRENTS AROUND THE NURSE CELLS AND VARIOUS AREAS AROUND GROWING OOCYTES. BOTH THESE IONS ARE IMPLICATED IN THE ELECTROPHYSIOLOGICAL POLARITY AND STEADY STATE CURRENTS. PRELIMINARY WORK IN JULY, 1994 REVEALED PREVIOUSLY UNKNOWN CA2+ CURRENTS THAT WERE NOT DETECTED WITH CONVENTIONAL WIRE PROBES. THERE HAS BEEN NO PREVIOUS STUDY OF THE TELEOTROPHIC OVARIOLE WITH THE ION-SELECTIVE PROBE. WITH OUR EXTENSIVE BACKGROUND WORK ON THE NET STEADY STATE CURRENTS, THE IMMUNOCYTO-CHEMISTRY OF THE CYTOSKELETAL CHANGES DURING OOGENESIS AND THE ULTRASTRUCTURAL ANALYSIS OF THE ENTIRE OOGENESIS CYCLE THE LIKELYHOOD OF LINKING ION SPECIFIC CURRENTS TO CELLULAR EVENTS LIKE NC-O TRANSPORT, OOCYTE POLARITY AND CYTOSKELETAL REORGANIZATION IS HIGH. DURING AN EXTENDED VISIT TO THE NVPF IN 1995/96, I INTEND TO MAP CA2+ AND NA+ CURRENTS OVER AN ENTIRE OOGENESIS CYCLE USING THE ION-SELECTIVE PROBE AND THEN PERTURB THESE CURRENTS WITH IONOPHORES AND CHANNEL BLOCKERS.